The exterior of the motor home is clad in 3 mm chequer plate aluminium with only the roof covered by 1 mm flat aluminium sheet. The roof is in any case covered by a tropical roof consisting of solar panels and 3mm chequer plate aluminium. 
I tried bonding it to the metal frame using VHB (Very High Bond) double sided tape ..
.. but had a few problems with that. I eventually settled on using Gold Flex - a cheap version of Sika Flex
Playing around with the Mitsubishi sign on the front of the truck  ;-)
We spray painted the whole thing in camo colours so that we would blend in with our surroundings.
Mixing the camo colours was fun ...
Close up of one of the doors for the storage bins giving an idea of the finished effect.
A picture with the extension of the body showing - it is the unpainted chequer plate bit.